Urbanization and carbon dioxide (CO2) emission nexus in the CEMAC countries

PurposeThis study investigates the relationship between urbanization and carbon dioxide emission in the Central African Economic and Monetary Community from 1990 to 2019. The literature reveals that the relationship between urbanization and carbon dioxide emissions is still debatable and the existing findings are inconclusive.Design/methodology/approachCarbon dioxide is the regressand; while, urbanization, gross domestic product (GDP) and financial development (FD), rule of law (ROL) and government effectiveness (GEF) are the regressors. Johansen Fisher and Kao residual co-integration tests alongside the fully modified and dynamic ordinary least squares.FindingsThe results show a significant positive relationship between urbanization and carbon dioxide emissions. The causality tests results show that carbon dioxide granger causes urbanization, GDP and FD unit directionally.Research limitations/implicationsThe countries' governments should effectively improve their legal systems to regulate carbon dioxide emissions. Urbanization laws should be implemented to limit urbanization environmental deteriorating effects on carbon dioxide emissions. This occurs as the countries practiced unregulated urbanization which increases population's environmental impacts. The study recommends sustainable green urbanization policies for environmental conservation through tree planting and horticulture. Balance development in urban and rural areas is vital to decongest the urban cities' pressure in the states. The governments should motivate the private sector with rural investments captivating policies to limit rural urban migration.Originality/valueThe findings contribute value by supporting a positive link between urbanization and carbon dioxide emissions in the CEMAC zone. The causality tests findings confirm the view that carbon dioxide granger causes urbanization, GDP and FD unit directionally. This value addition is essential to the governments and policy makers to mitigate urbanization and carbon dioxide emissions in the CEMAC region.

Differential Expression of lncRNAs and miRNAs Between Self-Rooting Juvenile and Donor Clones Unveils Novel Insight Into the Molecular Regulation of Rubber Biosynthesis in Hevea brasiliensis

The rubber tree (Hevea brasiliensis Muell. Arg.) is a tropical tree species that produce natural rubber. Self-rooted juvenile clones (SRJCs) are novel rubber tree planting materials developed through primary somatic embryogenesis. SRJCs have a higher rubber yield compared with donor clones (DCs). The molecular basis underlying increased rubber yield in SRJCs remains largely unknown. Here, the latex from SRJCs and DCs were collected for strand-specific and small RNA-seq methods. A total of 196 differentially expressed long noncoding RNAs (DELs), and 11 differentially expressed microRNAs were identified in latex between SRJCs and DCs. Targeted genes of DELs were markedly enriched for various biological pathways related to plant hormone signal transduction, photosynthesis, glutathione metabolism, and amino acids biosynthesis. DELs probably acted as cis-acting regulation was calculated, and these DELs relevant to potentially regulate rubber biosynthesis, reactive oxygen species metabolism, and epigenetic modification. Furthermore, the DELs acting as microRNA targets were studied. The interaction of microRNA and DELs might involve in the regulation of natural rubber biosynthesis.

ENVIRONMENTAL POLLUTION: EFFECT ON PEDESTRIANS WHILE WALKING IN URBAN STREET

Purpose: The reason for this study is because of observed difference in environmental condition in Lagos metropolis. The change is witnessed in environmental change arising from air, water and noise pollution mostly from increasing vehicle emissions in the State. This study has been conducted to analyze the environmental effects of pollution on pedestrians. Specific objectives are determine the air quality of the city at most populate headquarters of each of the 20 Local Government Areas of Lagos State, to examine the impact of pollution (air, water and noise) on pedestrians and assess various measures for reducing environmental pollution in the State. Methodology: The use of Thermo scientific MIE pDR-1500 instrument was used to measure air quality index of the selected locations and survey was carried out with well-structured questionnaire to elicit information with the aid of incidental sampling technique on impact of pollution on pedestrians from 177 respondents. Findings: Air Quality Index was shown with histogram chart where six out of 20 Local Government Areas are above the acceptable standard of pollution. There is rising cases of pollution in the State and very few Local governments were within acceptable range. One –Sample T-test showed that air pollution is majorly affecting pedestrians with t-value of 22.226 followed by noise with 19.643 and water with 5.529 respectively. Conclusion and recommendations: The research concluded that, there is need to control the rising cases of pollution in the state and policies to tame air and noise pollution in the state should be adopted. Emission control strategies to be adopted with the existing ones can be in form of restricting hours of movement of vehicles to late at night to avoid human pollutant contact, encourage tree planting and rapid evacuation of environmental waste.

Linking Tree Cover Change to Historical Management Practices in Urban Parks

ContextUrban parks provide critical ecological, health, and social benefits, constituting a substantial proportion of urban tree canopy (UTC) within a given city. As cities set ambitious UTC targets, it is critical to understand the social drivers of UTC changes in parks. ObjectivesWe sought to uncover the feedbacks between social processes, including historical events, and park UTC in a post-industrial city that experienced substantial population loss and urban park disinvestment. Methods Our mixed-methods approach involved quantifying spatiotemporal UTC changes and connecting those changes to historical management practices for three parks in Philadelphia, PA (US). We delineated UTC using aerial imagery between 1959 and 2018, and synthesized information from archival records and semi-structured interviews about historical management practices. ResultsWe found substantial UTC gains between 1959 and 1980, due to both: (a) budget cuts, mowing cessation, and associated unintended forest emergence; and (b) purposeful tree planting and reforestation activities. While some UTC gains were purposeful, others were unintentional and reflect successional processes on unmaintained lands. Contrary to literature suggesting that financial investment would lead to UTC gain, we saw declining UTC following an influx of new funding post-2000 due to construction and ecological restoration. ConclusionsWe found differing pathways leading to convergent outcomes of UTC gains. Across the three parks, differing historical processes and management goals for park landscapes had important ramifications for UTC. Our work suggests that landscape management could benefit from an improved understanding of how historical processes impact land cover.

Assessment of efficiency of urban plantations for noise reduction

Описано исследование эффективности использования городских насаждений для снижения уровня шума. В результате их применения эффективность снижения уровня шума изменялось от 1,1 дБА до 14,0 дБА. Наиболее эффективны для использования в шумозащитных целях многовидовые рядовые посадки деревьев с применением живых изгородей. Одновидовые живые изгороди, одновидовые и многовидовые рядовые посадки деревьев снижали уровень шума незначительно. Большую роль в снижении шума играла ширина полос зеленых насаждений. Зеленые полосы шириной 12,0-13,5 м снижали уровень шума на 9,3 дБА. The article describes the study of the efficiency of using urban plantations to reduce noise. As a result of their application, the noise reduction efficiency varies from 1,1 dBA to 14,0 dBA. Multi-view row tree planting using living fences is most effective for noise protection purposes. Single-species living fences, single-species and multi-species row tree planting reduced noise levels slightly. The width of green plantation lanes plays a major role in reducing noise. Green bands 12,0-13,5 m wide reduced noise level by 9.3 dBA.

Soil water deficit and recovery under different vegetation types on the Chinese Loess Plateau

Characterizing soil water content (SWC) dynamics is a prerequisite for conducting sustainable vegetation restoration on the Chinese Loess Plateau. However, quantifying the variations of the SWC in the deep soil layers remains a challenge because of the different driving factors and the complexity of surface processes. In this study, SWC in 0–10 m of artificial forestlands (AF), apple orchard (AO), native forestland (NF), farmland (maize; FL), and native grassland (NG) were monitored during 2019–2020. The deficit size (DS) and recovery index (RI) were used to explore the effects of vegetation types on SWC. The results showed that the SWCs of forestlands were significantly lower than the SWC of native grassland (12.32%) and tree species significantly affected the SWC. The monthly DS values in forestlands were negative, while those of FL were positive. The DS value in 0-10 m and predictive values below 10 m were negative of forestlands. Thus, tree planting may have consumed soil water at a depth of > 10 m. During the investigation period, soil water was restored in 0–1 m with the positive RI values. In addition, artificial forestlands showed good performance in deep soil water recovery. Canopy density was the controlling factor for soil water restoration. Our results demonstrated that the current afforestation mode used more soil water but was conducive to deep soil water conservation. Therefore, reasonable adjustments should be made according to the local soil and water resources for future vegetation selection and management.

A Novel Shaped Charge Engineered from Nano-metallic Glass Composite / High Entropy Alloy Liner for Debris Free Perforation Tunnel with Improved Reservoir Conductivity Leading to Enhanced Production

There is an unmet need for a clean perforating tunnel, for deep-water natural completions that reduces fluid friction, providing better reservoir connectivity and thus enhanced production. As a disruptive innovator in the technology space, particularly in the energy sector, we have now bridged this technology gap through the synthesis of a novel alloy, which when cold isostatic pressed into a conical shaped charge liner enables a unique response. During the detonation event, the jet created from our novel degradable liner punctures the casing and progresses to penetrate the formation until an eventual collapse. Our novel material is designed such that, during detonation, reaction products, bulk metallic glasses (BMG) and/or high entropy alloys (HEA), are formed which disintegrate into a fine powdery debris in contact with water. These degradable BMG/HEA or complexions are preferentially segregated at interfaces with high free energy. They tend to decorate the grain boundaries and domain interfaces of the impermeable skin lining the crushed zone of the perforation tunnel as amorphous intergranular films (AIFs) and plug at end of the pathway. Interacting with flowback fluids the complexions promote grain dropping, disintegrating the liner and carrot leaving behind a clean perforation tunnel. As a result, it is projected that fracture conductivity is significantly improved, resulting in enhanced productivity. In addition, a clear perf-tunnel has zero skin value. As such, when compared to a coated tunnel with gun and charge debris, it needs little or no acid to clean-up. In addition, it is anticipated that this will reduce the formation breakdown and opening pressures offering improved economics for the client. Last but not least, this leads to cost reduction of authorized field expenditure (AFE) to support optimized performance of completion designs allowing for increased production. The additional novelty of our liner designed through powder metallurgy (PM) techniques is a sub-sonic deflagration of the jet, during its collapse, resulting in sputtering of complexions and BMG/HEA residue along the perforation tunnel. These sputter-deposited jet complexions react with fluids during flowback, selectively being etched, barely needing water for the clean-up. The disintegration of this skin and slug, if any, in the perf-tunnel into fine particulates, subsequently being removed, leaves behind a clear, clean tunnel. CLEAR shaped charges have now been qualified to customer specifications in field conditions and are ready to be commercialized. Our journey of innovation does not end here. In fact, this is not even the beginning of the end, but it is, perhaps, the end of the beginning. To offset our carbon footprint and having embraced environmental and natural resources stewardship as one of our core values we are committed to contributing, as individuals and as an organization, to a flourishing human-ecological system. Through technology synthesis we have developed the concept of engineering seedpods for sustainable reforestation and Agri-tech. This had led to an endeavor for rapid tree planting through areal drones and UAVs’ to offset the effects of deforestation caused by human activities and natural disasters. In our paper we will additionally highlight this innovative technology cross-pollination and our efforts in low carbon and ESG endeavors.